The hippocampus is increasingly recognised for its role in working memory representations and goal-directed behaviour, yet whether these functions share common neural substrates remains unclear. We investigated short-term memory performance in 27 patients (21 males, 6 females) with LGI1-antibody limbic encephalitis (aLE), a condition with predominant hippocampal involvement, compared to 27 age- and gender-matched healthy controls, using an object-location continuous report task with Bayesian mixture modelling. Patients exhibited predominantly elevated misbinding errors-incorrectly associating objects with non-target locations-with unaltered guessing and only marginally reduced precision. Critically, apathy was positively as sociated with misbinding exclusively in patients, independent of depression and global cognition. Neuroimaging in a subset of patients (n = 12) revealed reduced hippocampal volumes and preliminary evidence for diminished hippocampal-medial prefrontal connectivity, which was associated with both higher apathy and increased misbinding at short retention intervals. These findings demonstrate that hippocampal dysfunction produces convergent deficits in memory binding and motivation, potentially reflecting disruption of a common brain mechanism linking working memory processing to goal-directed behaviour.Significance Statement The hippocampus, a brain region long associated with memory, is increasingly recognised for its role in goal-directed behaviour. We tested patients with autoimmune limbic encephalitis, a condition that primarily damages the hippocampus, on a working memory task that distinguishes different types of errors. Patients showed a predominant impairment in binding object identities to their locations, and these binding errors correlated with apathy-loss of motivation- independent of depression and general cognition. Reduced functional connectivity between the hippocampus and prefrontal cortex was associated with both higher apathy and greater binding errors. Our findings suggest that the hippocampus supports both memory and motivation through common neural mechanisms, with potential clinical implications for cognitive and motivational symptoms in hippocampal disorders.